The present invention relates to an image forming apparatus with a humidity measurement device.
In an image formation apparatus such as an electrophotographic copying machine or a printer, it is very important to control image forming conditions and adjust an image density so as to obtain a high-quality image. According to a conventional method of adjusting an image density, a surface potential of a photosensitive body is detected to control image forming conditions such as a charging amount and an exposure amount, thereby correcting influences caused by an atmospheric change of the photosensitive drum and its deterioration of over time. According to another conventional method, atmospheric conditions and the number of copy cycles (prints) are measured to correct the image forming conditions.
However, the charging characteristics of a toner during, e.g., a developing process of an electrophotographic apparatus are greatly influenced by humidity A toner exposed in a low humidity condition provides an image density different from a toner exposed in a high humidity condition even if identical image forming conditions are given. For this reason, in a conventional image forming apparatus, it is difficult to optimally adjust an image density to obtain a high-quality image.